CN103197238B - A kind of automotive relay coil releases energy method of testing - Google Patents

Abstract

The invention discloses a kind of automotive relay coil to release energy method of testing, the series circuit that this test circuit comprises the first stabilivolt and the first current-limiting resistance series connection formation is in parallel with the first metal-oxide-semiconductor, a termination 16 volts of power supplys of described relay coil, the drain electrode of the first metal-oxide-semiconductor described in another termination, one end of first current-limiting resistance is connected with the first stabilivolt, the other end ground connection after connecing the source electrode of the first metal-oxide-semiconductor, comprise step: A1, first time adhesive is done to described relay coil, disconnect after stable, release, the electric current of test circuit to described relay coil is sampled, obtain average current value I, A2, do second time adhesive to described relay coil, disconnect after stable, discharge, the voltage of test circuit to described relay coil is sampled, and obtains average voltage level U, A3, calculates described relay coil and releases energy wherein t is the release duration of described relay coil.

Description

A kind of automotive relay coil releases energy method of testing

Technical field

The invention belongs to technical field of automotive electronics, particularly a kind of automotive relay coil releases energy method of testing.

Background technology

Relay coil discharges the energy produced and can impact whole Circuits System, acts directly on the elements such as the transistor of drive coil, causes it to puncture inefficacy and cause peril.When relay coil is by moment when being closed into shutoff, because relay has the character of inductance, coil can produce self-excitation voltage to suppress the change of electric current.It is faster that coil current changes, and the reverse voltage of generation is higher.Upon release, the due to voltage spikes of a moment can be produced at the low pressure end of relay, usually can reach the decades of times of coil rating voltage.Drive the element of relay by the moment being conducting to closedown, relay coil can produce a very large self-induction electromotive force and supply voltage superposition on driving element, if the energy produced is large will be easy to punch through damage driving element, therefore will release energy to it between relay dispatches from the factory and test, ensure that product is qualified.For AUTOMOTIVE RELAY, especially need to test releasing winding energy.VW80932 standard required by Shanghai Volkswagen, the energy of general DC12V relay coil release is very safe within 3mJ, but existing method of testing, usually all do not meet the requirement of this standard.

Summary of the invention

The automotive relay coil that the object of this invention is to provide the VW80932 standard required by a kind of Shanghai Volkswagen of meeting releases energy method of testing.

Technical scheme of the present invention is, a kind of automotive relay coil releases energy method of testing, described relay coil access test circuit, this test circuit comprises the first metal-oxide-semiconductor, the first stabilivolt and the first current-limiting resistance, first stabilivolt and the first current-limiting resistance series connection formed series circuit in parallel with the first metal-oxide-semiconductor, a termination 16 volts of power supplys of described relay coil, the drain electrode of the first metal-oxide-semiconductor described in another termination, one end of first current-limiting resistance is connected with the first stabilivolt, the other end ground connection after connecing the source electrode of the first metal-oxide-semiconductor, comprise the following steps:

A1, does first time adhesive to described relay coil, and disconnect after stable, discharge, the electric current of test circuit to described relay coil is sampled, and obtains average current value I;

A2, do second time adhesive to described relay coil, disconnect after stable, discharge, the voltage of test circuit to described relay coil is sampled, and obtains average voltage level U;

A3, calculates described relay coil and releases energy , wherein t is the release duration of described relay coil.

In described steps A 1, after first time connection the first metal-oxide-semiconductor allows described AUTOMOTIVE RELAY adhesive stablize 1.5S, cut off the first metal-oxide-semiconductor to discharge by it, with the sampling rate of 10 μ S, continuous continual sampling is carried out to the voltage of the first current-limiting resistance, sampled value is magnitude of voltage, resistance again divided by the first current limliting sampling resistor obtains average current value I, and the resistance of the first current-limiting resistance is 22 ohm;

In described steps A 2, the theoretical voltage stabilizing value of the first described stabilivolt is 51 volts, after second time connection the first metal-oxide-semiconductor allows described AUTOMOTIVE RELAY adhesive stablize 1.5S, cuts off the first metal-oxide-semiconductor and discharges by it, first stabilivolt two ends continuous several times sampling is averaged, obtains average voltage level U.

In described steps A 3, the release duration t of described relay coil is when measuring average current value I in steps A 1, continuous sampling magnitude of voltage on the first current-limiting resistance, when releasing winding starts to be less than the time span of 0.05mV to this sample voltage value;

In described steps A 2, the stable foundation of average voltage level U is that 10 D appear in sampled data continuously _n+1-D _n<0, D _nbe the voltage sample value to the first stabilivolt two ends, N is positive integer.

Accompanying drawing explanation

Fig. 1 is the test circuit schematic diagram that the present invention adopts

Wherein, 1---AUTOMOTIVE RELAY, 2---relay coil, 3---51 volts of stabilivolts, 4---current-limiting resistance, 5---metal-oxide-semiconductor.

Embodiment

Can based on a kind of special test instrument to the test of automotive relay coil release produce power during specific implementation of the present invention.Requirement relay coil is DC12V.Consider that onboard system scope range of the fluctuation of voltage is 9V-16V, be carried in automotive relay coil test so set the maximum voltage value 16V likely occurred in actual use in testing.The main hardware that this test instrumentation is used comprises: the test board of C8051F005 single-chip microcomputer independent research, and adopt 12 high-precision ADC sampling tests, ADC internal reference voltage, sampling and process data is at every turn 10 μ S.The one-touch startup of this instrument, test process and result liquid crystal display, pilot lamp display and hummer instruction.

The automotive relay coil that the present invention relates to releases energy as E, U are the voltage at 51 volts of stabilivolt two ends adopted, and I is the electric current (as Fig. 1) flowing through 51 volts of stabilivolts.Because the intensity of variation of U when stabilivolt is breakdown is very small, the change of electric current is obviously, so this instrument is sampled to electric current with regard to emphasis.As can be caused the impact on number of samples to electric current and voltage sample simultaneously, current data can be lost more, has a strong impact on measuring accuracy, therefore takes the method allowing relay twice adhesive discharge to test more accurately.Its current value of first time release test, to its uninterrupted continuous sampling; Its magnitude of voltage of second time release test, uninterruptedly samples, averages.Stabilivolt is 51V, and current-limiting resistance is 22 Ω, and the metal-oxide-semiconductor response time is less than 8 μ S, and AD0+ and AD0-is differential voltage sampled point, and AD1+ and AD1-is difference current sampled point.

Performing step and main points are described below.

1. the stable rear release of first time adhesive, samples (AD1 passage) to electric current, measures the current value of each sampled point.Detailed process is, after connection metal-oxide-semiconductor stablizes 1.5S by relay adhesive, cut off metal-oxide-semiconductor to discharge by it, with the sampling rate of 10 μ S, continuous continual sampling is carried out to the current-limiting resistance below stabilivolt, sampled value is magnitude of voltage, be exactly its current value divided by sampling resistor (22 ohm) again, what now gather is digital quantity before AD conversion.Conversion formula is: U=2.43*DX/4096; Wherein U is the magnitude of voltage after AD transforms, and DX is the digital quantity value of sampling, and 2.43 is Chip Microcomputer A/D reference voltage levels, and 4096 be the ADC resolution of this single-chip microcomputer is 12, and corresponding digital quantity is exactly 4096 that is 2 ¹²(representing with 12 2 system numbers).Draw I=U/22 again; Namely current value equals magnitude of voltage divided by the current-limiting resistance of 22 ohm.

2. the stable rear release of second time adhesive, tests out the average voltage (AD0 passage) at 51 volts of stabilivolt two ends.Detailed process is, after connection metal-oxide-semiconductor stablizes 1.5S by relay adhesive again for the second time, cuts off metal-oxide-semiconductor and discharges by it, stabilivolt two ends multiple repairing weld is averaged, the 51V that stabilivolt should be constant in theory, but actual stabilivolt has and slightly fluctuates, and can increase the accuracy of test like this.U stabilivolt=(D (0)+D (1)+... + D (N))/(N+1), when voltage waveform by steadily to unexpected sharply decline time, illustrate that reverse voltage can not puncture stabilivolt, namely do not have electric current to flow through stabilivolt.(there are 10 D in adjacent sampled data continuously to utilize software programming program _n+1-D _n<0), judge that this turning point is positioned at the position of whole sampling array, just can determine effectively to puncture number of samples, thus obtain average voltage level.

3. for the determination of the release duration t of described relay coil, method is, each sampling spot and time coordinate can be formed with a graphics area, can be divided into a rectangle and one subtriangular.Due to instrument to each data sampling and store just in time need 10 μ S, so calculating each rectangle and leg-of-mutton bottom side length be 10 μ S.

4. last, the calculating that automotive relay coil releases energy is

$E=U*{{\&Integral;}^t}_{0}I\left(t\right)\mathrm{dt}$

Wherein I, t integrated curve figure can become several rectangles and several subtriangular by approximate segmentation

Following formula can be drawn:

E=U((S triangle is total)+(S rectangle is total))

S triangle is total=1/2 (D(0)-D(1)) * tc+1/2 (D (1)-D (2)) * tc+ ... + 1/2 (D(N-1)-DN) * tc

S rectangle is total=D (1) * tc+D (2) * tc+ ... + D (N) * tc

Wherein the unit of energy is MJ, D(0)---D(N) be efficiently sampling data, tc is 10 μ S.

5. about the process of sampled data, the digital quantity collected in whole process is greater than 8 and thinks valid data (0.05mV), simultaneously when collect digital quantity have 10 to be not more than the data of 8 continuously time, illustrate that dispose procedure terminates, judged by software like this, before first data being not more than 8, one is the data of DN, i.e. last release valid data.

The using method of instrument of the present invention is adopted to be:

1. plug in socket, opens power supply.

2., by good for two clip wire clamps of measured relay coil instrument, press startup and test.

3. test terminates rear automatic decision result, qualifiedly gives a green light, and hummer rings three sound soon; Defectively send out a warning, hummer is long rings a sound.(it is qualified that energy <=3mJ is judged as).

Claims (2)

1. an automotive relay coil releases energy method of testing, described relay coil access test circuit, this test circuit comprises the first metal-oxide-semiconductor, the first stabilivolt and the first current-limiting resistance, first stabilivolt and the first current-limiting resistance series connection formed series circuit in parallel with the first metal-oxide-semiconductor, a termination 16 volts of power supplys of described relay coil, the drain electrode of the first metal-oxide-semiconductor described in another termination, one end of first current-limiting resistance is connected with the first stabilivolt, the other end ground connection after connecing the source electrode of the first metal-oxide-semiconductor, it is characterized in that, comprise the following steps:

A1, does first time adhesive to described relay coil, and disconnect after stable, discharge, the electric current of test circuit to described relay coil is sampled, and obtains current value I;

A2, do second time adhesive to described relay coil, disconnect after stable, discharge, the voltage of test circuit to described relay coil is sampled, and obtains average voltage level U;

A3, calculates described relay coil and releases energy wherein t is the release duration of described relay coil.

2. automotive relay coil as claimed in claim 1 releases energy method of testing, it is characterized in that, in described steps A 1, after first time connection the first metal-oxide-semiconductor allows described AUTOMOTIVE RELAY adhesive stablize 1.5S, cut off the first metal-oxide-semiconductor to discharge by it, carry out continuous continual sampling with the sampling rate of 10 μ S to the voltage of the first current-limiting resistance, sampled value is magnitude of voltage, resistance again divided by the first current limliting sampling resistor obtains current value I, and the resistance of the first current-limiting resistance is 22 ohm;

In described steps A 2, the theoretical voltage stabilizing value of the first described stabilivolt is 51 volts, after second time connection the first metal-oxide-semiconductor allows described AUTOMOTIVE RELAY adhesive stablize 1.5S, cuts off the first metal-oxide-semiconductor and discharges by it, first stabilivolt two ends continuous several times sampling is averaged, obtains average voltage level U;

In described steps A 3, the release duration t of described relay coil is when measuring current value I in steps A 1, continuous sampling magnitude of voltage on the first current-limiting resistance, when releasing winding start to this sample voltage value be the time span of 0.05mV;

In described steps A 2, the stable foundation of average voltage level U is that 10 D appear in sampled data continuously _n+1-D _n<0, D _nbe the voltage sample value to the first stabilivolt two ends, N is positive integer.